function y = e_cliff(x)
% Extended Cliff  Function 
%x0=[0, -1, ......, 0, -1].  
%fmin=n/2
%Author:shi yangyang
n=length(x);
m=n/2;
z=ones(1,m);
for i=1:1:m
    temp1=(x(2*i-1)-3.0)/100.0;
    z(i)=temp1^2-(x(2*i-1)-x(2*i))+exp(20.0*(x(2*i-1)-x(2*i)));
end
y=sum(z);